Richardson fell Monday at the Mont Tremblant ski resort in Quebec. She initially appeared fine and joked about the fall, but the ski patrol insisted she see a doctor. Richardson declined, the resort said in a statement Tuesday.
Thursday, ABC News learned more details about what happened between when Richardson fell and when she sought medical attention. At 12:43 p.m. Monday, the first call to the paramedics was made. An ambulance arrived at 1 p.m. and transported Richardson from the foot of the mountain to the infirmary by sleigh.
Richardson thought she was fine and didn't want to stay at the infirmary. At 1:10 p.m., Richardson signed hospital waiver paperwork and walked 300 yards to hotel along with her ski instructor. She was back in her room by 1:30 p.m.
At 2:59 p.m., paramedics received a second call for help. An ambulance showed up at the hotel exactly ten minutes later. Richardson was conscious but showing signs that made paramedics call the hematology department at the Centre Hospitalier Laurentien in Ste-Agathe, where the ambulance took her.
Friday, the New York Times cited ambulance dispatch records showing Richardson was not admitted to a hospital until nearly four hours after her accident.
Richardson was later transferred to Hôpital du Sacre-Coeur in Montreal before being flown to New York City's Lenox Hill Hospital Tuesday, where her relatives rushed to her side.
On Tuesday night, Richardson's mother was seen entering the New York City hospital. So was Richardson's sister, Joely. Neeson also reportedly was by her side. Actress Lauren Bacall was photographed visiting the hospital Wednesday afternoon.
The Toronto Star reported that Richardson, lying heavily wrapped in blankets in an intensive-care bed, tubes covering her face, was loaded into an ambulance outside Montreal's Hôpital du Sacre-Coeur at 12:30 p.m. Tuesday, in preparation for her flight to New York.
Neeson was crouched down in the back of the ambulance watching as she was loaded, according to the Toronto Star.
Tuesday, the Mont Tremblant ski resort, released the following statement regarding her accident:
"Natasha Richardson fell in a beginners trail while taking a ski lesson at Station Mont Tremblant," the statement said. "She was accompanied by an experienced ski instructor who immediately called the ski patrol. She did not show any visible sign of injury but the ski patrol followed strict procedures and brought her back to the bottom of the slope and insisted she should see a doctor.
"As an additional precautionary measure, the ski instructor as well as the ski patrol accompanied Mrs. Richardson to her hotel," the statement continued. "They again recommended she should be seen by a doctor. The ski instructor stayed with her at her hotel. Approximately an hour after the incident Mrs. Richardson was not feeling good. An ambulance was called and Mrs. Richardson was brought to the Centre Hospitalier Laurentien in Ste-Agathe and was later transferred to Hôpital du Sacre-Coeur."
A spokesperson for the resort noted Richardson was not wearing a helmet while skiing and didn't collide with anything when she fell. Thursday, in the wake of her death, Quebec officials said they are considering making helmets mandatory on ski slopes, according to The Associated Press.